> ## Documentation Index
> Fetch the complete documentation index at: https://docs.contextual.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Lexical Search Weight

> `(lexical_alpha)`

## Description

When chunks are scored during retrieval (based on their relevance to the user query), this controls how much weight the scoring gives to exact keyword matches. A higher value means the agent will prioritize finding exact word matches, while a lower value allows for more flexible, meaning-based matching.

The value ranges from `0` to `1`, and Contextual AI defaults to `0.1`. You can increase this weight if exact terminology, specific entities, or specialized vocabulary is important for your use case.